Load arm for pressure rollers of draw frames



INVENTOR FRITZ STAHLECKER LOAD ARM FOR PRESSURE ROLLERS OF DRAW FRAMESJan. 9, 1962 ATTORNEYS 7 M W W W United States Patent 3,015,860 LOAD ARMFOR PRESSURE ROLLERS O DRAW FRAMES Fritz Stahlecker, Bad Uberkingen,Wurttemberg, Germany, assignor to Wilhelm Stahlecker G.m.b.H.,Reichenbach im Tale, Germany Filed Nov. 4, 1958, Ser. No. 771,800 Claimspriority, application Germany Nov. 5, 1957 9 Claims. (Cl. 19--135) Thepresent invention relates to improvements in draw frames of spinningmachines, and more particularly to a guide and load armfor depressingthe spring-loaded pressure rollers of a draw frame which are guidedwithin such a load arm so as to extend parallel to the axes of the lowerrollers and to be movable in a direction substantially vertical to thedrawing plane. a

For unlocking such a load arm, it is usually necessary to depress thisarm slightly at its front end. Since the pressure rollers of modern drawframes are often subjected to considerable loads, such operation ofdepressing the front end of the load arm for releasing the same so as topermit the arm to be pivoted upwardly requires considerable strength.

It is an object of the present invention to provide a very simple andinexpensive means for supporting the load arm in the operative positionand for easily releasing it from such position to permit it to bepivoted upwardly. For this purpose, the present invention provides theload arm with an additional arm which may be mounted on 3,015,860Patented Jan. 9, 1962 ICC FIGURE 5 shows a cross section taken alongline V-V in FIGURE 4; while FIGURE 6 shows a spring means for retainingthe releasearm of FIGURE 3 in retracted position.

Referring to the drawings, and first particularly to FIGURES 1 and 2,the guide and load arm 1 has a plurality of guide members 2 adjustablysecured thereto by bolts 3 which when loosened are slidable in slots 4.Pressure rollers 5 of the draw frame which are made in the form of twinrollers are guided by means of brackets 6 on guide members 2 and arecapable of moving between these brackets 6 in a direction substantiallyvertical to the drawing plane and parallel to the lower rollers 7. Theguide and load arm 1 is mounted in a known manner on a shaft 8 so as tobe pivotable in an upward direction. When arm 1 is thus pivoted, thepressure rollers 5 are held withinguide members 2 by means of lockingsprings 9.

According to the present invention, the load arm- 1 further carries aload-release arm 10 which is pivotably mounted thereon. When in theoperative position, release arm 10 will be pivoted backward and rest onload arm 1. For relieving the load on arm 1, the release arm 10 will bepivoted forward about a bolt 11 on load arm 1 so as to be in a position10', as indicated in FIGURE 1 in dotted lines, whereby the leverage fordepressing load arm 1 will be considerably increased. The operator ofthe loadarm so as to be either pivotable or slidable thereon and to bethus extensible relative to the load arm to increase the leverage of thelatter. I

A feature of the invention consists in making the loadrelease arm of aU-shaped cross section. According to one preferred embodiment of theinvention such U- shaped arm may be pivotably mounted at one end on theload arm so that, when the latter is in its operative position, therelease arm will closely engage with and embrace the load arm. Accordingto another preferred embodiment of the invention, the U-shaped releasearm may form a slide member which embraces the side walls of thecorrespondingly U-shaped guide and lo'ad'arm and is slidable forwardlyalong the same to extend the leverage of the load arm. For limiting theextent of the movement of the release arm, the same may be provided withsuitable stops which may, for example, consist of the heads of the boltsby which the guide brackets of the pressure rollers are mountedon theload arm and which engage in elongated slots in the release arm and areadapted to abut against the respective end walls of the slots when therelease arm is pulled out or retracted.

These and other objects, features, and advantages of the presentinvention will be more apparent from the following detailed descriptionthereof, particularly when read with reference to the accompanyingdrawings, in

which- FIGURE 1 shows a load arm according to the present invention inwhich the central and last pressure rollers which are supported in guidebrackets are loaded by a common torsion spring, while the startingroller is loaded separately by another torsion spring;

FIGURE 2 shows a cross section taken along line lIII of FIGURE 1;

FIGURE 3 shows a modification of the load arm acthe spinning machine maythen depress load arm 1 by acting upon the end of the extended releasearm 10. In the embodiment of the invention as shown in FIGURE 1, releasearm' 10 is made of a U-shape so as to engage closely with load arm 1when pivoted to its rear or rest position. This has the advantage thatthe release arm 10 thus has an adequate bending resistance withoutincreasing the thickness of load arm 1 since it does not extend abovethe heads of bolts 3 of guide members 2 of the pressure rollers 5.

The arm 10, especially if made of a U-shaped cross section, may,however, also be designed in the form of a slide member which is guidedalong the side arms of the correspondingly U-shaped load and guide arm 1by means of corrugations or guide bolts so as to be extensirelease armin the form of a slide member 12 of a cording to the invention, in whichthe release arm forms U-shaped cross section in the retracted or restposition on load arm 1, while FIGURE 4 shows slide member 12 in theextended position. On its upper surface, slide member 12 is providedwith two longitudinal slots 13 and 14 in which the heads of bolts 3slid'ably engage which secure guide members 2 of the pressure rollers 5(see FIGURE 1) to load arm 1. The forward movement of slide member 12 islimited by the rear end of slot 14 which engages with the head of themounting bolt 3 of guide member 2 of the central pressure roller. Therear end of load arm 1 is preferably provided with a tension spring 16which releasably engages an indented portion 17 of the rear end ofreleasearm 12 for normally retaining the same in the retracted or restposition.

Theembodiment of the invention according to FIG- URES 3 to 5 has theadditional advantage that, when the release arm 12 is in the retractedor rest position for the normal operation of load arm 1, it may alsoserve to increase the bending strength of load arm 1. For this purposeand for a more secure connection of release arm 12 'on load arm 1, thefree ends of the side walls of the U-shaped release arm 12 may be bentinwardly to engage underneath the lower edge of load arm 1, as indicatedparticularly at 15 in FIGURE 5. This embracing portion 15 may be madeeither of a narrow width as shown in FIGURES 3 and 4 or it may serve asa bracing member along a part or the entire length of load arm 1.Obviously, the release arm 10 according to the embodiment shown inFIGURE 1 may also be secured on load arm 1 when in the unpivo-tedposition as shown in full lines so as to serve as an additionalreinforcement of load arm 1 during the operation of the draw frame.

Although the invention has been illustrated and described with referenceto the preferred embodiments thereof, it should be understood that it isin no way limited to the details of such embodiments, but is capable ofnumerous modifications within the scope of the appended claims.

The invention having been fully disclosed, that which is claimed is:

1. In a draw frame for spinning machines having parallel upper and lowerpressure rollers, means for mounting said upper pressure roller-s so asto be adjustable in a substantially vertical direction relative to saidlower pressure rollers, said means comprising a load arm, said upperpressure rollers being rotatably mounted on said load arm, means formounting said load arm so as to be pivotable together with said upperpressure rollers relative to said lower pressure rollers, means forlocking said load arm in the downward position, and means for releasingsaid load arm from its looked position, said last means including asecond arm secured to said load arm but so as to be extensible therefromto increase the leverage of said load arm, said second arm having a restposition on said load arm and comprising means embracing said load armwhen said second arm is in said rest position.

2. A draw frame as defined in claim 1, wherein said second arm ispivotably mounted at one end on said load arm.

3. A draw frame as defined in claim 1, wherein said second arm is of aninverted U-shaped cross section and pivot-ably mounted at one end onsaid load arm so as to engage closely with and partly embrace said loadarm when pivoted upon the same.

4. In a draw frame for spinning machines having parallel upper and lowerpressure rollers, means for mounting said upper pressure rollers so astobe adjustable in a substantially vertical direction relative to saidlower pressure rollers, said means comprising a load arm, said upperpressure rollers being rotatably mounted on said load arm, means formounting said load arm so as to be pivotable together with said upperpressure rollers relative to said lower pressure rollers, means forlocking said load arm in the downward position, and means for releasingsaid load arm from its locked position, said last means including asecond arm secured to said load arm but so as to be extensible therefromto increase the leverage of said load arm, said second arm having a restposition on said load arm and comprising means embracing said load armwhen said second arm is in rest position, said second arm being of aninverted U-shaped cross section and slidably mounted on said load arm soas to be movable thereon from said rest position to an extendedposition.

5. A draw frame as defined in claim 4, wherein said pressure rollers areguided within brackets, said bracket being secured to said load arm bybolts, the heads of at least some of said bolts projecting above theupper surface of said load arm, said U-shaped second arm having at leastone elongated slot in its upper wall, said projecting bolt headsslidably fitting in said slot, the ends of said slot serving as stops todetermine the fully extended and rest positions of said second armrelative to said load arm.

6. A draw frame as defined in claim 4, further comp-rising resilientmeans for normally maintaining said second arm in the said restposition.

7. In a draw frame for spinning machines having parallel upper and lowerpressure rollers, means for mounting said upper pressure rollers so asto be adjustable in a substantially vertical direction relative to saidlower pressure rollers, said means comprising a load arm, said upperpressure rollers being rotatably mounted on said load arm, means formounting said load arm so as to be pivotable together with said upperpressure rollers relative to said lower pressure rollers, means forlocking said load arm in the downward position, and means for releasingsaid load arm from its locked position, said last means including asecond arm secured to said load arm but so as to be extensible therefromto increase the leverage of said load arm, said second arm having a restposition on said load arm and comprising means embracing said load armwhen said second arm is in rest position, said second arm being slidablymounted on said load arm.

8. In a draw frame for spinning machines having parallel upper and lowerpressure rollers, means for mounting said upper pressure rollers so asto be adjustable in a substantially vertical direction relative to saidlower pressure rollers, said means comprising a load arm, said upperpressure rollers being rotatably mounted on said load arm, means formounting said load arm so as to be pivotable together with said upperpressure rollers relative to said lower pressure rollers, means forlocking said load arm in the downward position, and means for releasingsaid load arm from its locked position, said last means including asecond arm secured to said load arm but so as to be extensible therefromto increase the leverage of said load arm, said second arm having a restposition on said load arm and comprising means embracing said load armwhen said second arm is in rest position, means on said second arm forretaining said arm on said load arm at least in said rest position andfor also reinforcing said load arm when the latter is in its operativeposition.

9. In a draw frame for spinning machines having parallel upper and lowerpressure rollers, means for mounting said upper pressure rollers so asto be adjustable in a substantially vertical direction relative to saidlower pressure rollers, said means comprising a load arm, said upperpressure rollers being rotatably mounted on said load arm, means formounting said load arm so as to be pivotable together with said upperpressure rollers relative to said lower pressure rollers, means forlocking said load arm in the downward position, and means for releasingsaid load arm from its locked position, said last means including asecond arm secured to said load arm but so as to be extensible therefromto increase the lever-age of said load arm, said second arm having arest position on said load arm and comprising means embracing said loadarm when said second arm is in rest position, said second arm beingslidably mounted on said load arm so as to be movable thereon from saidrest position to an extended position, said means embracing said loadarm constituting means for retaining said arm on said load arm at leastin said rest position and for also reinforcing said load arm when thelatter is in its operative position, said second arm being of aninverted U-shaped cross section, said side walls of said second armslidably engaging with the side walls of said load arm,-and inwardlybent extensions at the free lower end portions of said side walls ofsaid second arm slidably engaging with the lower edge portions of saidwalls of said load arm.

References Cited in the file of this patent UNITED STATES PATENTS

